Device for fusing xerographic images



July 20, 1954 c. R. MAYO DEVICE FOR FUSING XEROGRAPHIC IMAGES FiledSept. 26, 1952 w m m m CLYDE R. MAYO Patented July 20, 1954 DEVICE FORFUSING XEROGRAPHIC IMAGES Clyde R. Mayo, Rochester, N. Y., assignor tothe United States of America as represented by the Secretary of the ArmyApplication September 26, 1952, Serial No. 311,713

4 Claims. 1

This invention relates to electrophotography and more particularly to adevice for fixing or fusing xerographic powder images onto paper sheetsto produce final prints.

It is an object of the present invention to provide a strip fuser whichwill fuse a xerographic image using the vapor solvent condensationprinciple.

In accordance with the present invention, there is provided a device forfusing xerographic images comprising an upper vaporizing chamber and alower drip collecting chamber. The upper chamber is adjustably supportedupon the lower chamber and is spaced therefrom so that a substantiallyhorizontal slot of relatively constant height is provided therebetweenfor the passage of a sheet of paper. Within the upper chamber, there isa well for retaining a volatile liquid and heating means are provided toproduce vapor from this liquid. The lower face of the upper chamberforming the upper limit of the slot has an aperture in it to allowpassage of vapor from the well to the paper being developed. The upperface of the lower chamber forming the lower limit of the slot has aseries of openings serving as dripholes and both faces forming the slotslope down to these dripholes.

For a better understanding of the invention, together with furtherobjects thereof, reference is had to the following description taken inconnection with the accompanying drawings and its scope will be pointedout in the appended claims.

In the drawings Fig. l is a perspective view of a vapor fuser and Fig. 2is a perspective View, partially cut away, of the fuser, along line 22of Fig. 1.

Referring now more particularly to Figs. 1 and 2 there is shown an uppervaporizing chamber 3 which is closed except for a vapor slot 4 in thelower face 5 of the chamber. The remainder of the base of the chamberserves as a solvent well 6 surrounding the slot. The vaporizing chamber3 is adjustably supported on a lower drip-collecting chamber 1' by meansof a pair of adjustable end flanges connecting the end walls of saidchambers. This adjustability may be provided by any suitable means wellknown in the art such as slots 23 adapted to receive positioning stud24. Stud 24 is maintained in position within slot 23 by nut 25. Fig. 1shows one of such end flanges 8 connecting end Walls 2! and 22. A seriesof dripholes 9 are positioned directly under vapor slot 4. A stripheater It is clamped along one side of vaporizing chamber 3 near itsbottom edge and is powered from a variac auto-transformer (not shown) orother suitable means.- A pair of apertures II and 12 are provided inupper face i3 of the vaporizing chamber in which two immersionthermometers I4 and I5 may be mounted to check the solvent and vaportemperatures. That part of lower face 5 which comprises the base N3 ofthe well 6 in chamber 3 slopes medially downward from side walls 16 andIl. The upper face L) of lower chamber 1 has sloping portions on eitherside of the dripholes which are substantially parallel to base [8 ofwell 6 and a substantially horizontal space 20- of relatively constantheight for the passage of a sheet of paper or other suitable material isprovided between base I8 of well 6 and. upper face IQ of chamber 1.

In operation, the height of the chamber 3 above the chamber 1 isadjusted by connecting flanges 8 to provide a gap of approximatelyone-quarter inch or any other suitable spacing. The solvent well 8 ispartly filled with a volatile solvent such as perchlorethylene and powerapplied to heater it. When using perchlorethylene, a vapor temperaturein the range of between C. and C. appear to give the best results. Aftera preliminary warm-up period, a 20-25 watts input to the strip heater issuificient to maintain a vapor temperature in the desired range.Different solvents having the proper vapor pressure and other necessaryproperties may be used.

Sheets of paper carrying powder images, passed through the paper slotwith the image side facing upward, are fixed by a single pass takingthree seconds for an eleven inch length of paper. Microscopic comparisonof fused and unfused images indicate that little or no loss ofdefinition is associated with solvent fixing.

While there has been described what is at present considered to be thepreferred embodiment of the invention, it will be obvious to thoseskilled in the art that various changes and modifications may be madetherein without departing from the invention, and it is, therefore,aimed in the appended claims to cover all such changes and modificationsas fall within the true spirit and scope of the invention.

What is claimed is:

1. A device for fusing xerographic images comprising an upper vaporizingchamber and a lower drip collecting chamber, said upper chamber beingadjustably supported upon and spaced from said lower chamber to providea substantially horizontal slot of relatively constant heighttherebetween for receiving material having said image, means foradjusting the height of said slot, a plurality of spaced wells withinsaid upper chamber for retaining a volatile liquid, means for heatingsaid liquid to produce vapor, the face of said upper chamber formingupper limit of said slot having an aperture therein to allow passage ofsaid vapor to said material, the face of said lower chamber oppositesaid upper chamber face having therein a plurality of dripholes disposedunder said aperture, both of said faces tapering inwardly to saiddripholes.

2. A device for fusing xerographic images as in claim 1 wherein saidmeans for adjusting height of said slot comprises a plurality ofadjustable fianges connecting said chambers.

3. A device for fusing xerographic images as in claim 1 wherein saidmeans for heating said liquid comprises a strip heater.

4. A device for fusing xerographic images comprising an upper vaporizingchamber and a lower drip collecting chamber, said upper chamber beingadjustably supported upon and spaced from said lower chamber to providea substantially horizontal slot of relatively constant heighttherebetween for receiving material having said image, a pair ofadjustable flanges connecting end walls of said chambers, a well withinsaid upper chamber for retaining a volatile liquid, a strip heaterattached to said upper chamber to produce vapor from said liquid, theface of said upper chamber forming upper limit of said slot having anaperture therein to allow passage of said vapor to said material, theface of said lower chamber opposite said upper chamber face havingtherein a plurality of dripholes disposed under said aperture, both ofsaid faces tapering inwardly to said dripholes.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,795,220 Langener Mar. 3, 1931 2,009,962 Kurten July 30, 19352,172,783 Alink et a1 Sept. 12, 1939 2,333,733 Morse Nov. 9, 1943

1. A DEVICE FOR FUSING XEROGRAPHIC IMAGES COMPRISING AN UPPER VAPORIZINGCHAMBER AND A LOWER DRIP COLLECTING CHAMBER, SAID UPPER CHAMBER BEINGADJUSTABLY SUPPORTED UPON AND SPACED FROM SAID LOWER CHAMBER TO PROVIDEA SUBSTANTIALLY HORIZONTAL SLOT OF RELATIVELY CONSTANT HEIGHTTHEREBETWEEN FOR RECEIVING MATERIAL HAVING SAID IMAGE, MEANS FORADJUSTING THE HEIGHT OF SAID SLOT, A PLURALITY OF SPACED WELLS WITHINSAID UPPER CHAMBER FOR RETAINING A VOLATILE LIQUID, MEANS FOR HEATINGSAID LIQUID TO PRODUCE VAPOR, THE FACE OF SAID UPPER CHAMBER FORMINGUPPER LIMIT OF SAID SLOT HAVING AN APERTURE THEREIN TO ALLOW PASSAGE OFSAID VAPOR TO SAID MATERIAL, THE FACE OF SAID LOWER CHAMBER OPPOSITESAID UPPER CHAMBER FACE HAVING THEREIN A PLURALITY OF DRIPHOLES DISPOSEDUNDER SAID APERTURE, BOTH OF SAID FACES TAPERING INWARDLY TO SAIDDRIPHOLES.